The transcription factor TaMYB31 regulates the benzoxazinoid biosynthetic pathway in wheat

Zhaniya S. Batyrshina, Reut Shavit, Beery Yaakov, Samuel Bocobza, Vered Tzin

Research output: Contribution to journalArticlepeer-review

11 Scopus citations

Abstract

Benzoxazinoids are specialized metabolites that are highly abundant in staple crops, such as maize and wheat. Although their biosynthesis has been studied for several decades, the regulatory mechanisms of the benzoxazinoid pathway remain unknown. Here, we report that the wheat transcription factor MYB31 functions as a regulator of benzoxazinoid biosynthesis genes. A transcriptomic analysis of tetraploid wheat (Triticum turgidum) tissue revealed the up-regulation of two TtMYB31 homoeologous genes upon aphid and caterpillar feeding. TaMYB31 gene silencing in the hexaploid wheat Triticum aestivum significantly reduced benzoxazinoid metabolite levels and led to susceptibility to herbivores. Thus, aphid progeny production, caterpillar body weight gain, and spider mite oviposition significantly increased in TaMYB31-silenced plants. A comprehensive transcriptomic analysis of hexaploid wheat revealed that the TaMYB31 gene is co-expressed with the target benzoxazinoid-encoded Bx genes under several biotic and environmental conditions. Therefore, we analyzed the effect of abiotic stresses on benzoxazinoid levels and discovered a strong accumulation of these compounds in the leaves. The results of a dual fluorescence assay indicated that TaMYB31 binds to the Bx1 and Bx4 gene promoters, thereby activating the transcription of genes involved in the benzoxazinoid pathway. Our finding is the first report of the transcriptional regulation mechanism of the benzoxazinoid pathway in wheat.

Original languageEnglish
Pages (from-to)5634-5649
Number of pages16
JournalJournal of Experimental Botany
Volume73
Issue number16
DOIs
StatePublished - 12 Sep 2022

Keywords

  • Abiotic stress
  • Rhopalosiphum padi aphid
  • Spodoptera littoralis caterpillar
  • Tetranychus urticae spider mite
  • Triticum aestivum
  • Triticum turgidum
  • biotic stress
  • herbivores
  • specialized metabolites

ASJC Scopus subject areas

  • Physiology
  • Plant Science

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